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androidandroid-audiorecord

Why do I get nothing but zero from the output of audiorecord?


I want to use an AudioTrack to play a sound and I recorded it using AudioRecord at the same time. But I cant get anything except zero. Why?

I have tried to read data from the byte[] buffer and all I get is zero. Here is my code:

import java.io.BufferedOutputStream;
import java.io.DataOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Time;
import java.util.Timer;
import java.util.TimerTask;

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;

public class RecordThread implements Runnable {

private static final int Encording = AudioFormat.ENCODING_PCM_16BIT; //Data size for each frame = 16 bytes
private static final int Sample_rate = 8000;                         //Sample rate = 8000 HZ
private static final int Channel = AudioFormat.CHANNEL_IN_MONO;      //Set as single track
public static final int Buffersize = AudioRecord.getMinBufferSize(Sample_rate, Channel, Encording); //Buffer size
@Override
public void run() {
    // TODO Auto-generated method stub

    AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,Sample_rate, Channel, Encording, Buffersize);
    while(MessageUsed.RecordPermit){
    try {
        FileOutputStream ops = new FileOutputStream(TestoOFDMMain.file2);
        BufferedOutputStream bos = new BufferedOutputStream(ops);
        DataOutputStream dos = new DataOutputStream(bos);

        byte[] buffer = new byte[Buffersize]; 


            audioRecord.startRecording();   //Start Recording
            int bufferReadResult = audioRecord.read(buffer, 0, buffer.length);  //Read Array size
            MessageUsed.RecordStop = false;
            /*Write Data to file*/
            for(int i=0;i<bufferReadResult;i++){
                dos.write(buffer[i]);
            System.out.println(buffer[i]);  
                if(MessageUsed.ProcessPermit == true){
                        break;
                    }
                }

        audioRecord.stop();
        dos.close();
        MessageUsed.RecordStop = true;
        Thread.sleep(300);
        MessageUsed.ProcessStart = true;

        Thread.sleep(900);

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    }
}
}

Solution

  • I would assume on a quick glance that your System.out.println() statement is not allowing the result to appear. That's a basic java expression- not Android java. The 0 you are seeing could be the default value of whatever field you are looking at.